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Peltodoris nayarita
Photographed at Punta Engenia, Baja California Sur, June, 1998
In 1981, Jesús Ortea and Eva María Llera described a new species of dorid nudibranch that had been collected 25 April 1980 from Isla Isabel, Nayarit, México (21 52' N; 105 54' W). Their description was based on only one specimen, which had been collected with its egg mass. They state (my translation), "The only specimen collected was not able to be examined alive." The drawing they present is of the "moribund" organism.
Before I continue with a description of this species, I need to comment that the original article contains a confusing generic placement. The authors seem to synonymize and separate the genera Peltodoris and Anisodoris. Without going into details, they are separate genera, and this species is correctly placed in Peltodoris (see also Millen & Bertsch, in press).
Because it is difficult to find this article, let me present parts of the original manuscript.
MORFOLOGIA EXTERNA: "Midió 14 mm de largo por 7 mm de ancho. Manto de color amarillo oro, con manchitas pardas esparcidas por toda su superficie. En la zona media hay una mayor concentración de manchas pardas, lo que unido a la coloración de las vísceras da a esa zona una tonalidad castaño.
"Superficie del manto cubierta por numerosos y pequeños tubérculos cónicos espiculosos (9 por mm lineal).
"Abertura rinofórica elevada, manchada de pardo. Rinóforos castaño oscuro.
"Abertura branquial también elevada, con 8 horas unipinnadas de raquis muy ancho, amarillento, y laminillas castaño oscuro.
"Pie amarillo, surcado y hendido anteriormente; much más corto que el manto en el animal fijado.
ANATOMIA: "Cutícula labial sin armazón.
"Rádula formada por dientes ganchudos simples de fórmula 51 x 50-0-50. Los 7 primeros dientes son muy pequeños y de forma muy igual, leugo van aumentando progresivamente de tamaño hasta el número 48, el 49 y 50 son más pequeños y el último es una cuña simple y gruesa.
"El resto del aparato digestivo está representado en la fig. 3. La fijación del material en alcohol de caña no permitió una buena observación de los órganos internos.
"El aparato genital es de tipo seriado, con el espermatocisto y la bolsa copulatriz esféricos. Todos los conductos genitales son muy cortos. Hay una porción prostática del conducto deferente bien diferenciada. El pene es inerme.
BIOLOGIA: "La puesta es una cinta de color naranja de 3 mm de alto arrollada en espiral de tres vueltas.
ORIGEN DEL NOMBRE: "La especie la denominamos A. nayarita en honor del Estado de Nayarit, México, en donde se encuentra la Isla Isabel."
And now a Hans Bertsch translation of the above (keep quiet Dr. Ángel Valdés):
EXTERNAL MORPHOLOGY: The animal measured 14 by 7 mm. The mantle was a gold yellow color, with brownish spots spread throughout the entire surface. In the center of the notum there is a greater concentration of brown splotches, which joined with the coloration of the viscera, give this area a specially hazel (=castaño) tone.
The surface of the mantle is covered with numerous small, conical, spiculous tubercles (9 per linear mm).
The rhinophore aperture is elevated, brownish speckled. The rhinophores are a dark hazel.
The branchial aperture is also raised, with 8 unipinnate gills from a narrow rachis, yellowish, with the platelets a dark hazel.
The yellow foot is bilabiate and notched anteriorly; in the preserved animal it was much shorter than the mantle.
ANATOMY: Labial cuticle unarmed.
Radula consists of simple hooked teeth, with a formula of 51 x 50-0-50. The 7 innermost teeth are very small and of a similar shape. The teeth progressively increase in size until number 48, and then numbers 49 ad 50 become much smaller; the outermost tooth (number 50) is reduced to just a simple small, thick nail.
The rest of the digestive system is illustrated in fig. 3. The fixation of the specimen in "cane alcohol" did not allow a good observation of the internal organs.
The genitalia are of the serial type, with the spermatocyst and the bolsa copulatrix both spherical. All the genital ducts are very short. There is a prostatic portion of the deferent duct that is well differentiated. The penis is unarmed.
BIOLOGY: The egg mass is an orange-colored belt, 3 mm high, in a spiral of 3 turns.
ETYMOLOGY OF THE SPECIFIC NAME: We named this species A. nayarita in honor of the State of Nayarit, México, where Isla Isabel occurs.
And now, the rest of the story (to quote the radio newscaster Paul Harvey). The illustrated animal (from the center of the outer coast of the Baja California peninsula) is the first picture of a living specimen of this species. Orso Angulo Campillo and I collected it 15 August 1998 in 6 m of water, while scuba diving about 1 km NE of Punta Eugenia (27 51' N; 115 05' W), Baja California Sur. In addition to being only the second specimen ever reported, our organism represented a significant northward range extension of nearly 1300 km from the center of the Panamic faunal province, and its first reported occurrence in nearly 20 years (see Bertsch, Angulo, and Arreola, 2000).
Hopefully more individuals will be found so we can learn something about
its biology.
LITERATURE CITED
Bertsch, Hans, Orso Angulo Campillo, and José Luis Arreola. 2000. New
distributional records of opisthobranchs from the Punta Eugenia region of
the Baja California peninsula: a report based on 1997-1998
CONABIO-sponsored expeditions. The Festivus 32 (7): 99-104.
Millen, Sandra V., and Hans Bertsch. In press. Three new species of
dorid nudibranchs from southern California, U.S.A., and the Baja
California peninsula, México. The Veliger 43 (4).
Ortea, Jesús, and Eva María Llera. 1981. Un nuevo dórido (Mollusca:
Nudibranchiata) de la Isla Isabel, Nayarit, México. Iberus 1: 47-51.
Grateful acknowledgement is made to
Robert Williamson, José Luis Arreola, Orso Angulo Campillo, and to Tom Smith.
Imperial Beach, California
Aug, 2000
Taxonomy text and photos courtesy of Dr. Hans Bertsch
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| Dr. Hans Bertsch, Tom Smith, and Orso Campillo
Assoc. Prof. |
